C / C++ / MFC

15-May-02 23:33

Why ?

It's a resource dll, just make your own.

Christian

The tragedy of cyberspace - that so much can travel so far, and yet mean so little.

And you don't spend much time with the opposite sex working day and night, unless the pizza delivery person happens to be young, cute, single and female. I can assure you, I've consumed more than a programmer's allotment of pizza, and these conditions have never aligned. - Christopher Duncan - 18/04/2002

Re: How to modify a DLL

Nish Nishant16-May-02 0:42

Nish Nishant

16-May-02 0:42

Just open it in Visual Studio and set the file type as Resource and you can now edit the bitmaps Smile | :)

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Traversing array

alex.barylski15-May-02 22:55

15-May-02 22:55

Sorry if my terminology is wrong. Smile | :)

Anyways...How would I iterate an array of the following structure:

struct ITEM{
  LPSTR Parent
  LPSTR Caption
  UINT Command
  ITEM Child 
}

I'm NOT looking for a C++ solution, but a generic psuedo-language answer would be GREAT!!!

I'm losing my mind trying to figure out how this would be done...if the array were simple it would be easy even if the number of levels were known it would be easier...a couple nested for loops would suffice. However...when each last field is a pointer to another just like it (but slightly different) that simple array transforms into something...I can't comprehend and it's driving me insane...

Anyone ever deal with such a data structure before...?

I thought this was a linked list or sort of anyways, but I can't just follow one elemnt to the next...I have to iterate each item in the array...

ie:

if there were 5 items, each had ZER0 children except the last which had 5 levels of 5 children each how would I loop through this kinda array and return all data...?

I'm playing with the idea of a windows menu data structure and my god...i'm lost...

Any ideas...?

Thanx! Smile | :)

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Jon Hulatt15-May-02 23:03

Jon Hulatt

15-May-02 23:03

Your main problem here is that you have a recursive definition. Creating an ITEM in turn creates another ITEM, which creates another ITEM etc.

It would be considerably wiser to redefine like this:

struct ITEM{  
  LPSTR Parent  
  LPSTR Caption  
  UINT Command  
  ITEM *Child 
}

This way, you create all the ITEM's you need and no more.

Anyway, a suitable way to look at all these it to recurse. Just like you would to walk a directory structure:-

void RecurseItems(ITEM *p_Item)
{
  cout << "Got an ITEM at %X" << (DWORD) p_Item << "\n";
  if (Child != NULL)
    RecurseItems(Child);
}

That'll do the job.

Jon

STL is a religeon. Enquiries to Reverend Christian Graus

Christian Graus15-May-02 23:20

15-May-02 23:20

I'm pleased we both came up with the same solution, although it doesn't meet his requirements ( pointers are not exactly a cross language phenomenon, in that lots of languages don't have them ).

I'm chuffed by your sig as well, but there's only one s in Graus Rose | [Rose]

Christian

The tragedy of cyberspace - that so much can travel so far, and yet mean so little.

And you don't spend much time with the opposite sex working day and night, unless the pizza delivery person happens to be young, cute, single and female. I can assure you, I've consumed more than a programmer's allotment of pizza, and these conditions have never aligned. - Christopher Duncan - 18/04/2002

Jon Hulatt15-May-02 23:21

Jon Hulatt

15-May-02 23:21

Apologies, i'll correct it now!

STL is a religeon. Enquiries to Reverend Christian Graus

alex.barylski16-May-02 1:08

16-May-02 1:08

A NULL child already indicates no child/sub-items are available for that particular item though...?

Like a windows drop down menu...what kinda data structure would that require...?

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Jon Hulatt16-May-02 2:52

Jon Hulatt

16-May-02 2:52

I have no idea what you're on about.

STL is a religeon. Enquiries to Reverend Christian Graus

Christian Graus15-May-02 23:05

15-May-02 23:05

while (item)
{
// use the other members

item = item.Child;
}

Make item a POINTER to an ITEM, and use NULL to specify the bottom item. Otherwise you need a data memeber or magic number combination to show the end of the line. If it's a loop ( the last item points to the first ) then it's like this

ITEM item = (whatever)
ITEM item2 = item

while(true)
{
//deal with item

item = item.Child;

if (&item == &item2)
break;
}

so where-ever you start, when you end up at the beginning, you break.

Christian

The tragedy of cyberspace - that so much can travel so far, and yet mean so little.

And you don't spend much time with the opposite sex working day and night, unless the pizza delivery person happens to be young, cute, single and female. I can assure you, I've consumed more than a programmer's allotment of pizza, and these conditions have never aligned. - Christopher Duncan - 18/04/2002

alex.barylski16-May-02 1:04

16-May-02 1:04

Hey Christian...thanx for the reply...

Your correct about the pointer assumption...i'm actually using JScript to develope a menu in DHTML with unlimited children popup's...

Each AppendMenuItem() basically takes as parameters
Caption, Parent, CommandID and adds them to the array as needed.

If i'm to create a menu from a array I fail to see how the above would create all the popups and items in each...I have tried the above before and i'm obviosuly missing a important link... Blush | :O

File    Edit    View
New     Undo    History  ->>> Object1
Open    Redo    ---------     Object2
Save            Wireframe     Object3
                Solid

In order to create all the popups I would need to iterate the array and when the end of a division was reached i'd need to stop and start back where I began, no...?

I'm thinking I need some nLevel variable to track my last known position...perhaps an array of nLevels...?

How does the code above allow me to find an item with a particular caption...?

Sorry for not getting it or repeating questions...

Thanx! Smile | :)

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Christian Graus16-May-02 1:05

16-May-02 1:05

OK - that changes things a LOT. Your orignal model cannot work, because it does not allow multiple children of one parent. I *do* know that you can have arrays in JScript, so one way would be for an ITEM to store an array of children, if it's empty, then it's an end item, otherwise it contains the children of that item.

Christian

The tragedy of cyberspace - that so much can travel so far, and yet mean so little.

And you don't spend much time with the opposite sex working day and night, unless the pizza delivery person happens to be young, cute, single and female. I can assure you, I've consumed more than a programmer's allotment of pizza, and these conditions have never aligned. - Christopher Duncan - 18/04/2002

alex.barylski16-May-02 13:14

16-May-02 13:14

Christian Graus wrote:
OK - that changes things a LOT.

I was afraid of that.

Arrays are possible in JScript so are custom struct's sorta.

//Custom struct
function MENU_ITEM(Caption, Parent, CommandID)
{
  this.Caption   = Caption;
  this.Parent    = Parent;    //NULL for toplevel
  this.CommandID = CommandID; //NULL if child exists
  this.Child     = new Array();
}

// Add items to array

var MenuItems = new Array();

var nItems = MenuItems.length;

MenuItems[nItems] = new MENU_ITEM("File", null, null);
MenuItems[nItems].Child = new MENU_ITEM("MRU1", "File", 1000);
MenuItems[nItems+1].Child = new MENU_ITEM("MRU2", "File", 2000);
MenuItems[nItems+2].Child = new MENU_ITEM("MRU3", "File", 3000);

The above is what I am trying to accomplish and have almost got it...

a Menubar is created with only a File item and it has 3 children MRU list...how do I iterate the array above, considering children can have children and so on...

thats whats confusing the heck outta me...i'm so lost on how to set up the loop... Confused | :confused:

Would I use 2 nested for loops or a while loop...?

Can you suggest any other approach/structure to managing drop down menus...?

Thanx again! Smile | :)

"An expert is someone who has made all the mistakes in his or her field" - Niels Bohr

Christian Graus16-May-02 13:29

16-May-02 13:29

Hockey wrote:
how do I iterate the array above, considering children can have children and so on...

Recursion

A function needs to take an ITEM, then it needs to iterate through the array of items in it something like this

RecurseThroughMenu(ITEM item)
{
foreach (ITEM i in item.Child)
{
// add item i to the menu under 'item'
if (i.Child.length > 0)
RecurseThroughMenu(i)
}
}

This is not meant to be any particular language, just give you the idea how to do it Smile | :)

alex.barylski16-May-02 13:52